That’s because there’s never been a phone or smartphone to have this kind of problem. I tried covering my LG enV Touch on Verizon with my hand and got it to lose 1X but it still had 3 bars of EVDO which means no dropped call. Even then, I had to use both hands to cover enough of it to make a difference, something you won’t do while talking. Even my dad’s 4 year old POS HTC that get’s terrible ATT reception to start with doesn’t drop calls when you palm the back.
A guy my dad works with got an iPhone4 on release day and the Apple Store told him that he had to buy a case and a new SIM card to fix the reception problems. Being a typical Apple fan, he obeyed and is still dropping calls like crazy. This case thing is just a quick and cheap way to make people think their problems aren’t related to the phone; it doesn’t actually solve any problems.
Phones are typically designed around the concept that they WON’T lose their network connection while being used. Apple cared more about sleek, pretty, light, and iPhoneish than they did actual functionality and usefuness and I hope it’s a mindset they adopt in their PC engineering.